1. Field of the Invention
The present invention relates to a trim member or interior furnishing use in a motor vehicle, which is composed of a unitary assembly of a covering sheet, an instrument panel, and a foamed body, and a method of and an apparatus for manufacturing such a trim member.
2. Description of the Background Art
Trim members used as interior furnishings which incorporate a motor vehicle instrument panel are mostly grained on their outer surface to give a realistic impression of leather. More specifically, a trim member of synthetic resin is embossed to give its outer side a leather-like appearance which makes the trim member look rich and sophisticated. To make such a grained trim member soft to the touch, the trim member includes a composite sheet comprising a foamed sheet of vinyl chloride applied as a cushioning layer to a leather sheet of vinyl chloride.
Generally, there have widely been adopted two methods of manufacturing grained trim members for automobiles. According to the first method, a covering sheet which is embossed on its outer surface is softened with heat and held against one pressure mold member of a molding device, and a core member coated with an adhesive on the surface to be adhered to the covering sheet is held against another pres sure mold member. Then, the pressure molding members are pressed against each other to join and form the covering sheet and the core member to a desired shape, thus completing a trim member.
According to the second method, a covering sheet which has been softened with heat is attracted under vacuum to an embossing mold member of a molding device. The embossing mold member is in the form of a porous electro-formed mold member. Thereafter, a core coated with an adhesive and held against another mold member is pressed against the covering sheet which has been attracted to the embossing mold member, thereby producing a trim member.
If a trim member including a motor vehicle instrument panel is to be manufactured by these conventional methods, since the trim member to be fabricated is large in size and complex in shape, the trim member has to be formed as two or three separate sections, and then the formed sections have to be joined together. The entire manufacturing process is complicated and requires a number of steps because two or three separate sections have to be formed first to make up a single trim member.
Another problem is that when the formed separate sections are joined together, the lines along which they are joined remain visible on the outer surface of the trim member. As a result, the completed trim member does not look like a unitary body and is poor in appearance because of steps or surface irregularities which are present along the joint lines. Inasmuch as the trim member is made up of the joined sections, the entire rigidity of the trim member is relatively low, and the trim member tends to squeak while the motor vehicle is running. The trim member is also heavy since the core member is used to reinforce the covering sheet.
To the trim member manufactured by the conventional methods, there are attached, by screws, various parts such as ducts, boxes, etc. The overall assembly is thus less resistant to creep. Therefore, after use over a certain period of time, the trim member becomes less rich and sophisticated. Moreover, the overall assembly cannot be assembled with ease, so that the entire manufacturing process is poor in efficiency.
The covering sheet used with the instrument panel is considerably large and complex in shape. Consequently, it is difficult to grain the covering sheet uniformly over its entire surface area, and it is awkward to remove the embossed covering sheet from a impressing mold assembly.